I. Field
The present invention relates generally to communication, and more specifically to techniques for transmitting and receiving multiplex protocol data units (MUX-PDUs) in a wireless communication system.
II. Background
Wireless communication systems are widely deployed to provide various communication services such as voice, video, packet data, and so on. These systems may be multiple-access systems capable of providing communication for multiple users by sharing the available system resources (e.g., the system bandwidth and/or transmit power). Examples of such multiple-access systems include a Code Division Multiple Access (CDMA) system, a Time Division Multiple Access (TDMA) system, a Frequency Division Multiple Access (FDMA) system, and an Orthogonal Frequency Division Multiple Access (OFDMA) system.
Videophone or video telephony is a rapidly growing application for many wireless communication systems. A videophone application transmits voice and video simultaneously using, for example, ITU-T Recommendation H.223 (or simply, “H.223”), entitled “Multiplexing Protocol for Low Bit Rate Multimedia Communication.” H.223 is a protocol that receives video, audio, data, and control as separate media streams and generates MUX-PDUs for all of these streams. The MUX-PDUs are then mapped to, or encapsulated within, PHY packets, which are packets at a physical layer (PHY). The PHY packets are further processed and transmitted via a wireless channel to a receiver.
The receiver typically receives some percentage of PHY packets in error due to noise and impairments in the wireless channel. The PHY packets received in error are often called erased PHY packets. Typically, all MUX-PDUs carried in the erased PHY packets are also lost. Since erased PHY packets are inevitable for a wireless system, there is a need in the art for techniques to reduce the number of lost MUX-PDUs due to the erased PHY packets.